1. Field of the Invention
The present application relates generally to construction products, and in particular to an apparatus for a water proof component void form to create space between concrete structures and expansive soil.
2. Description of Related Art
A plurality of structures are built on and in expansive soils. Once poured and hardened, a concrete structure in contact with the expansive soil may develop cracks and ultimately fail if the soil heaves or moves. Therefore, building codes and engineering specifications often require the formation of a gap, often referred to as a void space, between the concrete structure and the expansive soil to act as a buffer from soil movement.
Typically, a method of generating a void space has been to use a 100% paper based corrugated paper product that is laid along the ground prior to pouring the concrete. The paper product is used as part of the form for the concrete. The paper product includes some measures to resist water absorption due to contact with wet concrete and the soil, however, these measures are only temporary. In time, the paper product deteriorates from the absorption of water and loses its strength after the concrete has set. This creates a space into which soil can expand without causing damage to the concrete.
A problem with using paper based products is that the product is only water resistant and not water-proof. When soil is saturated, conventional paper products cannot be used. Paper void forms absorb moisture and standing water, and deteriorate too quickly. When deteriorating, the strength of the paper material is greatly reduced. Some ways to compensate for these deficiencies have been for manufacturers to overly design their forms with excess paper material. This is done to maximize the strength of the form structure in the event of moisture exposure. A problem with this is obviously the cost and waste of excess materials. Ultimately, paper forms are too susceptible to moisture levels and too difficult to predict their strength at end use when manufacturing the form.
Void forms are designed to specific strength ratings. A form should be sufficient to hold the concrete pour and permit soil fluctuations without affecting the concrete. Over strengthened void forms from the use of excess paper products tend to be too strong and can transfer soil movements to the concrete, thereby causing foundation issues. On the other hand, if exposed to too much moisture, void forms become prematurely weak in order to support the foundation during concrete placement. A better product is needed to allow more accurate and predictable results that minimize the effect of moisture and the amount of material used to produce a form.
In operation, time is required to set a series of paper void forms in place to pour the concrete structure. The surface soil must be prepared, the paper void forms must be placed, ¼″ protection board placed upon the entire carton form surface, and the rebar must be laid out prior to pouring concrete. This process could take anywhere from a number of hours to a number of days depending on the size of the project, project design and jobsite conditions. If rain or saturation of the soil occurs at any point prior to pouring concrete, the foundation may be compromised. The forms would need to be removed and discarded, and the work would have to be redone.
Given the present use of paper void forms, in order to minimize the effects of moisture, a water proof covering can be used. However, such coverings tend to limit or prevent proper ventilation within the paper void form. By not having sufficient air movement, a concern is that humidity can become trapped below the covering. If the paper product becomes saturated, the structural integrity may be compromised. Such concerns and procedures to ensure proper storage and application can lead to loss of product, increased expenses, and lost time.
Although great strides have been made with respect to forming the void space between concrete structures and expansive soil, it is obvious that considerable shortcomings remain with the conventional paper based void forms. A new type of corrugated construction product is needed.
While the application is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the application to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the application as described herein.